This application concerns a multifaceted program intended to define and quantify blood-materials interactions, using several animal models and eventually the limited use of human volunteers as a source of blood. The blood-materials interactions will be studied using several analytical techniques which will qualitatively and quantitatively assess the molecular level interactions which take place at the surface. The majority of this study will involve the use of whole, unaltered blood, avoiding the problems arising from the use of nonphysiological solutions or suspensions of blood components. The program will extend past efforts which have identified protein adsorption as the initial reaction which then governs further interactions as for example, those of the formed elements. Fourier Transform infrared spectroscopy (FT-IR), ellipsometry, scanning electron microscopy (SEM) and radioimmune assay (RIA) techniques will all be employed in this investigation. Extensive feasibility studies employing FT-IR have demonstrated that information on absorbed protein conformations, adsorbed protein layer composition and protein adsorption kinetics can be readily obtained when blood plasma or serum is employed. Use of cylinderical attenuated total reflection (ATR) optics with ultra-high sensitivity infrared detectors will permit use of whole, uncoagulated blood. The ATR/FT-IR combination technique will be backed up by ellipsometry for protein layer thickness determinations, RIA for specific protein and platelet release factor analysis and SEM for surface morphology and formed elements determinations. Effects on platelet survival and leukocyte phagocytic activity will also be determined in this study.